https://commons.ufh.ac.za/vital/access/manager/Index ${session.getAttribute("locale")} 5 https://commons.ufh.ac.za/vital/access/manager/Repository/vital:38941 Wed 12 May 2021 22:23:41 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:6910 Wed 05 Apr 2023 07:00:23 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:29200 Tue 31 Aug 2021 12:17:53 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:35580 Tue 22 Jun 2021 11:22:44 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:6569 Tue 18 Jul 2023 21:51:59 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:6830 8.5°C, salinity >34.2), suggesting that the SAF lay extremely far to the south. In the southeast corner water masses were typical of the Antarctic zone, showing a distinct subsurface temperature minimum of <2.5°C. Total integrated chl-a concentration during the survey ranged from 4.15 to 22.81 mg chl-a m[superscript (-2)], with the highest concentrations recorded at stations occupied in the frontal region. These data suggest that the region of the South-West Indian Ridge represents not only an area of elevated biological activity but also acts as a strong biogeographic barrier to the spatial distribution of zooplankton.]]> Thu 01 Sep 2022 09:36:41 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:35579 Mon 30 Aug 2021 14:59:02 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:6965 Mon 30 Aug 2021 14:52:02 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:6832 Mon 30 Aug 2021 14:45:03 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:6901 Mon 30 Aug 2021 14:38:04 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:6935 Mon 30 Aug 2021 14:38:03 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:6834 Mon 30 Aug 2021 14:38:02 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:6881 Mon 30 Aug 2021 14:31:05 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:6548 Mon 30 Aug 2021 14:31:02 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:6928 200 μm) was investigated on three occasions in a warm temperate, temporarily open/closed estuary situated along the southern African coastline. Results of the investigation indicated that the microheterotrophs represented the most important consumers of bacteria and chlorophyll (chl)-a <5.0 μm. The low impact of the mesozooplankton on the bacteria and chl-a <5.0 μm during the study appeared to be related to the inability of the larger zooplankton to feed efficiently on small particles. During those periods when total chl-a concentration was dominated by picophytoplankton (<2.0 μm) and microphytoplankton (>20 μm), mesozooplankton were unable to feed efficiently on the chl-a due to feeding constraints. In response to the unfavorable size structure of the phytoplankton assemblages, mesozooplankton appeared to consume the microheterotrophs. The negative impact of the mesozooplankton on the microheterotrophs resulted in a decrease in the impact of these organisms on the bacteria and the chl-a <5.0 μm. This result is consistent with the predator-prey cascades. On the other hand, when the total chl-a was dominated by nanophytoplankton (2–20 μm), mesozooplankton were able to feed directly on the phytoplankton. Results of the study indicate that size structure of the phytoplankton assemblages within estuaries plays an important role in mediating the trophic interactions between the various components of the plankton food web.]]> Mon 30 Aug 2021 14:31:02 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:29201 Mon 30 Aug 2021 14:24:06 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:6886 Mon 30 Aug 2021 14:24:04 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:29224 Mon 30 Aug 2021 14:24:04 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:35630 Mon 30 Aug 2021 14:24:03 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:29758 Mon 30 Aug 2021 14:24:02 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:29194 Mon 30 Aug 2021 14:17:09 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:29219 Mon 30 Aug 2021 14:17:08 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:38239 Mon 30 Aug 2021 14:17:07 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:29203 Mon 30 Aug 2021 14:17:07 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:29220 Mon 30 Aug 2021 14:17:05 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:29222 Mon 30 Aug 2021 14:17:04 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:29197 Mon 30 Aug 2021 14:17:03 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:38213 Mon 30 Aug 2021 14:17:03 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:38238 Mon 30 Aug 2021 14:17:02 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:29190 Mon 30 Aug 2021 14:10:03 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:29195 Mon 30 Aug 2021 14:10:02 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:38214 Mon 30 Aug 2021 12:53:07 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:29187 Mon 30 Aug 2021 12:53:06 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:29181 Mon 30 Aug 2021 12:53:05 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:29444 Mon 30 Aug 2021 12:53:04 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:29440 Mon 30 Aug 2021 12:53:03 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:29185 Mon 30 Aug 2021 12:53:03 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:29169 Mon 30 Aug 2021 12:46:08 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:29172 Mon 30 Aug 2021 12:46:08 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:35590 Mon 30 Aug 2021 12:46:07 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:29174 Mon 30 Aug 2021 12:46:06 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:29168 Mon 30 Aug 2021 12:46:06 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:29179 Mon 30 Aug 2021 12:46:04 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:35514 0.05) between the diatom indices’ values and the nutrient variables. The absence of any significant correlations between the diatom indices’ values and selected physico-chemical variables suggests that indices developed in other regions of the world may not be suitable for temperate southern African rivers.]]> Mon 30 Aug 2021 12:46:03 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:40439 Mon 30 Aug 2021 12:46:03 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:29170 Mon 30 Aug 2021 12:46:02 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:6966 0.05). The zooplankton community was dominated, numerically and by biomass, by mesozooplankton comprising mainly copepods of the genera, Oithona,Paraeuchaeta, Pleuromamma, Calanus and Clausocalanus. An exception was recorded at those stations in the region of the front where the tunicate, Salpa thompsoni, dominated the total zooplankton biomass.]]> Mon 14 Aug 2023 12:18:12 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:29189 Mon 08 Aug 2022 09:21:02 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:6934 Mon 03 Apr 2023 12:03:38 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:6933 20 μm) species composition and distribution along a repeat transect between Cape Town and the Prince Edward Islands were investigated in early austral autumn (April/May) 1996. Samples were collected at approximately 30 nautical mile intervals for the analysis of size-fractionated chl-a and the identification and enumeration of microphytoplankton species. Peaks in total chl-a (>1 μg 1 [superscript -1]) were recorded at the Subtropical Convergence (STC), at the Sub-Antarctic Front (SAF) and in the waters surrounding the Prince Edward Islands. In addition, a minor peak in chl-a concentration was recorded in the continental shelf waters. At stations where elevated chl-a concentrations were recorded, microphytoplankton generally formed a substantial contribution (-10%) to total chlorophyll. Outside these regions, total chlorophyll concentrations were lower (<0.9 μg 1 [superscript -1]) and almost entirely dominated by nano- and picophytoplankton, which contributed >95% of the total. Microphytoplankton species composition along both transects were dominated by chain-forming species of the genera Chaetoceros (mainly C. neglectum, C. peruvianus and C. constrictus), Nitzschia spp. and Pseudoeunotia doliolus. Cluster and ordination analysis based on species composition identified five distinct microphytoplankton assemblages, which were closely associated with the different water masses in the region between Cape Town and the Prince Edward Islands. The microphytoplankton species composition and biogeographic zones identified during this investigation are in general agreement with similar studies conducted in the south-west Indian Ocean during the austral summer, which suggests that there are little seasonal trends in both the microphytoplankton species composition and biogeographic zonation.]]> Mon 03 Apr 2023 12:03:27 SAST ]]> https://commons.ufh.ac.za/vital/access/manager/Repository/vital:6967 Mon 03 Apr 2023 10:18:00 SAST ]]>